Cohesive Release Loads in a General Finite Element Model of a Propagating Crack

Abstract:

High speed MODE I crack growth in elastic-plastic materials, involving large scale plasticity and dynamic effects connected to rapid propagation, is faced through a cohesive model to tune force nodal release. The stress resisting to the opening of the edges in the cohesive zone should account of effective stress field ahead crack tip. In this paper a reference value is accounted: it represents the maximum closing stress measured at the crack tip, where the cohesive effects begin. A bi-parametric analytical formulation of stress distribution ahead the crack tip is suggested. The bi-parametric formulation is able to extrapolate the stress at the tip whatever is the T-stress (i.e. the stress acting in the direction of fracture propagation), thus completely defining the cohesive loads.

• Periodical: Key Engineering Materials (Volumes 417-418)
• Pages: 517-520
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.417-418.517
• Online since: October 2009
• Authors: A. Fontana, M. Minotti, Pietro Salvini
• Keywords: Cohesive Release Model, Finite Element Model (FEM), Fracture Mechanic

References

[1] Needleman A.: An analysis of tensile decohesion along an interface. J Mech Phys Solids 1990; Vol. 38, pp.289-324.

DOI: 10.1016/0022-5096(90)90001-k

[2] Ortiz M, Pandolfi A.: Finite-deformation irreversible cohesive elements for three-dimensional crack-propagation analysis. Int. J. for Numerical Methods in Eng. 1999; Vol. 44, pp.1267-82.

DOI: 10.1002/(sici)1097-0207(19990330)44:9<1267::aid-nme486>3.0.co;2-7

[3] Hillerborg A.: Application of the Fictitoius Crack Model to Different Materials, International Journal of Fracture , 1991, Vol. 51, pp.773-782.

[4] J.W. Hutchinson, Singular behavior at the end of a tensile crack in a hardening material. Journal of the Mechanics and Physics of Solids, 1968, Vol. 16, pp.13-31.

DOI: 10.1016/0022-5096(68)90014-8

[5] J.R. Rice and G.F. Rosengren, Plane strain deformation near a crack tip in a power-law hardening material. Journal of the Mechanics and Physics of Solids, 1968, Vol. 16, pp.1-12.

DOI: 10.1016/0022-5096(68)90013-6

[6] Betegon C, Hancock J.W. Two Parameter Characterization of Elastic-Plastic Crack Tip Fields, Journal of Applied Mechanics, 1991, Vol. 58, pp.104-110.

DOI: 10.1115/1.2897135

[7] Cotterel B., Reddel J.K. The essential work of plane stress fracture, Int. Journal of Fracture, 1977, Vol. 13, pp.267-277.

DOI: 10.1007/bf00040143

[8] Berardo, G., Salvini, P., Di Biagio M. The Application of cohesive model to dynamic ductile fracture tests, XIII European Conf. on Fracture, Elsevier, San Sebastian (Spain), Sept. 2000. Mesh transition Free propagation.